The purpose of this research protocol is two determine whether 1) hypogonadism contributes to the loss of weight and lean body mass characteristic of the AIDS Wasting Syndrome (AWS), and 2) testosterone administration will enhance endogenous GH secretion in this hypogonadal population. Advanced HIV disease is a highly catabolic state characterized by the profound and disproportionate loss of lean body mass in association with severe weight loss. Because hypogonadism has been documented in a significant percentage of men with the AWS, the investigators hypothesize that a deficiency of the potent anabolic hormone, testosterone, facilitates the catabolic state in advanced HIV disease. In addition, hypogonadism results in diminished secretion of endogenous Growth Hormone (GH) which may further contribute to the loss of lean body mass in the AWS. Physiologic androgen replacement is known to improve nitrogen balance, lean body mass and endogenous GH secretion in other hypogonadal populations, but has not been studied in men with AIDS. The goal of this proposal is to determine the anabolic effects of androgen replacement in hypogonadal men with the AWS. The protocol is designed as a 12 month, randomized, double blind, placebo-controlled, single crossover trial. All potential study candidates will be screened at an outpatietn isit after informed consent is given to determine gonadal function, CD4 count, hemoglobin and platelet levels. From these initial studies 50 hypogonadal men will be identified. Informed consent for the protocol will be obtained from appropriate candidates, who will then return to the GCRC as outpatients on 4 sequential days to receive injections of GnRH and to collect urine for urea nitrogen and creatinine.